Uf, Ψ, Thermal bridges, Isotherms, fRsi


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WINISO® is the expert software for the calculation of heat flows, thermal bridges, isotherms and Uf values according to EN ISO 10077-2:2018. Imported CAD files can be processed with automatic recognition and correction of CAD errors. Thus, complicated components and systems can be analyzed and calculated with short computing times and small data sizes. The integrated CAD editor and the FEM calculator core, in combination with the validated calculation method and the new ISO 10077-2:2018 standard, enable the user to achieve a very accurate calculation result. After over a year of development the new WINISO® is available.


For more than 20 years, the widely used WinIso2D software has been established in many areas of building physics. New standard specifications and the constant progress in window and facade technology result in increasing demands on the calculation software. The FEM calculator core contained in WINISO® enables a precise and validated calculation of any CAD files in a very short time. Users of WinIso2D will not only find all the usual functions in the new software, but also the processing and calculation possibilities will be extended by numerous features, which describes only one of the many advantages of the new WINISO.

The software solution „WINISO®“ includes the following features:

  • Highly automated geometry preparation of CAD data (.dxf und .dwg)
  • Detailed transfer of CAD data incl. radii and bevels
  • Automatic material assignment using CAD layers
  • New solver and new calculation core with automatic FEM networking
  • Calculation according to the “radiosity model” (new cavity model according to
    EN ISO 10077-2:2018) and with equivalent conductivity (EN ISO 10077-2:2012/
  • Simple definition of foils, coatings and surface properties using polylines
  • Gas filling for inter-pane spaces according to EN 673 freely miscible
  • Automated Uf calculation of window and facade profiles
  • Psi values of thermal bridges and insulating glass spacers according to EN ISO
    10211 and EN ISO 10077-2
  • Ug values of multiple panes of insulating glass according to DIN EN 673
  • U-values of any construction according to EN ISO 6946
  • Calculation of isotherms, surface temperatures and temperature factor
  • Vapor diffusion calculation



For our expert software WINISO® for the calculation of heat flows, thermal bridges, isotherms and Uf values according to EN ISO 10077-2:2018 the add-on “Humidity” is available for the calculation of relative humidity, vapour diffusion and condensation water failure.

The following evaluation modes are available with the “Humidity” add-on:

Relative humidity fields

The display provides information about the quality of the profile/component. The darker the spots in the profile, the greater the relative humidity, i.e. the risk of condensation. The calculated value Psat is the saturation vapour pressure at the point in the component. It is temperature-dependent and indicates the maximum amount of water the component can absorb in Pa at the respective point.

Pi is the partial water vapour pressure at the respective point. The partial pressure is adjusted by the boundary conditions and the heat transfer in components and cavities. If the partial pressure exceeds the saturation pressure, the component is “supersaturated” at the point in consequence condensation water precipitates.

Vapour diffusion flow fields

It shows how much water in g/m*d flows through a component. The water vapour flow runs through a component in the same way as the temperature curve. This means that the water vapour flows along the partial pressure gradient from high to low. The resistance number μ is decisive for the diffusion current through a component. The larger the number, the more impermeable the building material is.

Condensation loss

If the partial pressure Pi exceeds the saturation vapour pressure Psat, condensation occurs in the profile. Common causes are low temperatures and low diffusion resistance figures μ of the individual components. Places where condensation precipitates are marked in blue.

ISO 15099

Our expert software WINISO® has been extended by the calculation according to the American standard ISO 15099. The “ISO 15099” add-on is available for this purpose.

With the add-on “ISO 15099” the relevant calculations of Ufr-, Ueg– and Ucg-calculations according to ISO 15099 and NFRC can be carried out. Once the calculation is complete, you can generate the printout specifically for ISO 15099 and receive a list of the materials used. The calculation results with the corresponding Imperial units are also specified.

Batch processing